[PATCH] score: Direct thread dispatch in a self restart

[Gedare Bloom]

ok, tricky case.

On Fri, May 21, 2021 at 8:57 AM Sebastian Huber
<sebastian.huber at embedded-brains.de> wrote:
>
> Commit 73ebf9a27ed5cd0fd3e0dc0da98345d7faa610a2 accidentally removed the
> direct thread dispatch in a self thread restart.  In case of a self
> restart (always in task context) the directive shall not return.  If
> this is not possible due to a bad thread dispatch disable level, then a
> fatal error shall occur.
>
> Update #4412.
> ---
>  cpukit/score/src/threadrestart.c | 16 +++++++++++-----
>  1 file changed, 11 insertions(+), 5 deletions(-)
>
> diff --git a/cpukit/score/src/threadrestart.c b/cpukit/score/src/threadrestart.c
> index e4e123b9f0..79a154e3d3 100644
> --- a/cpukit/score/src/threadrestart.c
> +++ b/cpukit/score/src/threadrestart.c
> @@ -539,6 +539,7 @@ Status_Control _Thread_Restart(
>  {
>    Thread_Life_state    previous;
>    Per_CPU_Control     *cpu_self;
> +  bool                 is_self_restart;
>    Thread_Life_state    ignored_life_states;
>    Thread_queue_Context queue_context;
>
> @@ -550,11 +551,10 @@ Status_Control _Thread_Restart(
>    }
>
>    cpu_self = _Thread_Dispatch_disable_critical( lock_context );
> +  is_self_restart = ( the_thread == _Per_CPU_Get_executing( cpu_self ) &&
> +    !_Per_CPU_Is_ISR_in_progress( cpu_self ) );
>
> -  if (
> -    the_thread == _Per_CPU_Get_executing( cpu_self ) &&
> -    !_Per_CPU_Is_ISR_in_progress( cpu_self )
> -  ) {
> +  if ( is_self_restart ) {
>      ignored_life_states = THREAD_LIFE_PROTECTED | THREAD_LIFE_CHANGE_DEFERRED;
>    } else {
>      ignored_life_states = 0;
> @@ -582,7 +582,13 @@ Status_Control _Thread_Restart(
>    _Thread_Wait_release( the_thread, &queue_context );
>
>    _Thread_Priority_update( &queue_context );
> -  _Thread_Dispatch_enable( cpu_self );
> +
> +  if ( is_self_restart ) {
> +    _Thread_Dispatch_direct_no_return( cpu_self );
> +  } else {
> +    _Thread_Dispatch_enable( cpu_self );
> +  }
> +
>    return STATUS_SUCCESSFUL;
>  }
>
> --
> 2.26.2
>
> _______________________________________________
> devel mailing list
> devel at rtems.org
> http://lists.rtems.org/mailman/listinfo/devel